The above referred to process, for example, preferably involves feeding the pieces to wrapping and sealing stations of the machine in equally spaced positions on an infeeding conveyor above which is fed at a higher speed a continuous strip of the sheet of wrapping material. The infeeding conveyor sometimes comprised a continuous belt or chain moved generally horizontally in an elongated continuous path in a vertical plane and carrying fingers engaging the rear ends of the pieces sliding along a horizontal slotted table. The fingers pushed the pieces to the sealing station of the machine where they then leave contact with the pieces. While the pieces to be wrapped are moved horizontally by these fingers along the slotted table to the sealing section of the machine the strip of sheet material is draped down over the sides of the pieces on the slotted table. The pieces with the sheet material draped along the sides thereof are then delivered by these fingers to the sealing station of the machine where the pieces to be Wrapped are then moved along the slotted table by the friction of the wrapping material pressing against the sides of the pieces, in some cases aided by inwardly spring-urged strips pressing the moving strip against the sides of the pieces to be wrapped.
At the inlet portion of the sealing station the longitudinally extending bottom margins of the strip of wrapping material are first brought together beneath the pieces to be wrapped where they are sealed together in any suitable way along their longitudinal margins, as by heat sealing where the strip is made of thermoplastic material. The wrapped pieces are then delivered by the forces applied to the pieces by the moving strip of sheet material pressing against the sides thereof to an end sealing and preferably also a sheet severing station where the then top and bottom layers of the continuous sheet of wrapping material are cross sealed together just beyond the opposite longitudinal ends of each piece. The cross sealer preferably comprises confronting top and bottom rotating drums carrying circumferentially spaced sealing and severing ribs which first cross seal and severe the sheet material at the front end of the leading piece delivered thereto and then cross seal and severe the sheet material at the rear end of the latter piece.
In order for the prior art wrapping machines to reliably deliver the partially wrapped pieces to the cross sealing station just described, the pieces must be properly spaced on the slotted table or the cross sealing and severing ribs could smash the pieces delivered thereto. The frictional forces of the inwardly pressed sides of the sheet of wrapping material maintained such proper spacing reliably only if the speed of the movement thereof was severely limited. Otherwise the pieces could readily shift longitudinally on the slotted table to a point where the cross sealing and severing ribs described would contact and crush the improperly positioned pieces.